Starter-throttle interconnection



April 25, 1944. a. BURRELL THROTTLE INTERCONNECTION Filed July 13, 1940 S TARTER- 2 Sheets-Sheet l (Ittqrnegs April 25, 1944. GIBURRELL STARTER-THROTTLE INTERC(JNI IEC.I'IONv Filed July 13, 1940 2 Sheets-Sheet 2 Gil/int 181177511 Patented Apr. 25, 1944- UNITED STATES PATENT OFFICE 2,347,251 STARTER-THROTTLE INTERCONNECTION Gilbert Burrell, Lansing, Mich, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application July 13, 1940, Serial No. 345,317

12 Claims. (Cl. 123- 179) To facilitate starting the propelling engine, there are provided on some makes of automotive vehicles an interconnection by which actuation of the starter pedal, button or whatnot cracks the throttle valve of the carburetor of the engine before it closes the started switch. These interconnections, however, do not take into account the circumstance that the optimum position of the throttle valve during the starting operation varies with the temperature of the engine and to this extent are defective.

The principal object of this invention is to provide an interconnection between the starter pedal, button or whatnot and the throttle valve of the carburetor of an internal combustion engine which is so constructed and arranged that the extent to which the throttle valve is open during the starting operation will be greater when the engine is cold than when it is hot and thus obviates the mentioned defect in the interconnections which are in use.

Another object of the invention is to provide an interconnection between the starter pedal, button or whatnot and the throttle valve of the carburetor of an internal combustion engine which is so constructed and arranged that the extent to which the throttle valve is open during the starting operation will be determined by the adjustment of the stop by which the movement of the throttle valve toward its closed position is limited and accurate adjustment of the interconnection to regulate the extent to which the throttle valve is open during the starting operation thus obviated. I

More specifically, the invention has to do with internal combustion engines whose carburetors are equipped with thermostatic devices by which the extent to which their throttle valves may be moved toward their closed positions when the engines are cold is limited and has for its object to provide an interconnection between the starter pedal, button or whatnot and the throttle valve of the carburetor of such an engine which is so constructed and arranged that movement of the starter pedal, button or whatnot to start the engine will first opentthe throttle valve to an extent beyond the maximum to which the thermostatic device ever holds it open, thus permitting the thermostatic device to assume the position dictated by the prevailing temperature, and then, before the startingvmotor is put into operation, releases the throttle valve and permits it to move toward its closed position to the extent permitted by the thermostatic device, thus, simtion in accordance with my invention between the starter button and the throttle valve of the carburetor of the propelling engine;

Figure 2 is an enlarged view of the interconnection and associated parts shown in Figure 1;

Figure 3 is a further enlarged perspective of a portion of the interconnection shown in the preceding figures;

Figure 4 is a view which corresponds to a portion of Figure 1 but in which the parts of the interconnection are in different positions than in Figure l;

Figure 5 is a rear elevation of the engine and associated parts shown in the preceding figures;

Figure 6 is a side elevation of the carburetor and associated parts of the engine shown in the preceding figures.

In the drawings the reference character Ill indicates the internal combustion propelling engine and the reference character II the fioor board of the driver's compartment of an automotive vehicle.

The engine I0 is equipped with a carburetor l2 which includes a throttle valve l3 by which the rate at which combustible mixture is supplied to the cylinders and thus the speed of the engine is regulated and a choke valve I4 by which the richness of the combustible mixture supplied to the cylinders is regulated.

The choke valve I4 is of the butterfly type and is mounted ona shaft [5 which is journaled in the walls of the body oi the carburetor. On one end of the shaft IBacam I6 is mounted so that when the choke valve moves from its opened toward its closed position it carries the cam with it but that the choke valve may move in the opposite direction without corresponding movement of the cam. The earn 16, however, has a weighted tail I! which when the cam is unrestrained causes it to follow the movement of the 'choke valve in the latter direction and tends to move the choke valve toward its opened position. The choke valve is also unbalanced so that its unbalanced weight and flow of air into the carburetor tend to move it toward its opened position and has connected to the end of its shaft l5 opposite that on which the cam I6 is mounted a thermostatic coiled spring [8 which when the temperature of the engine is below a predetermined value yieldingly opposes movement of the choke valve toward its opened position with a force that varies inversely as the temperature of the engine. -Thlls,"When the-temperature of the engine is below the predetermined value, the

position of the choke valve l4 and, when the cam is unrestrained, the position of the cam l6, is

determined by the unbalanced-weights of'the; p

choke valve I4 and the tail I! of the cam, the

rate of flow of air through the carburetor and the temperature of the engine; The throttle valve 13 is also of the butterfly type and is mounted on a shaft l9 which is jour-.

naled in the Walls of the body of thecarburetor and has secured to one of its ends a three-armed lever 20. To one arm of the lever there is connected a link 2| which hasalost motion connection with one arm of a two-armed lever 22 which is mounted on the body of the carburetor in such a position that a set screw 23 which extendsthrough its other arm may be moved into engagement with the cam l6 on the choke valve shaft l5 against the resistance of a spring 24. Through another arm of the three-armed lever 20 there extends a set screw25 which may en- 5 gage anabutment 26 on the body of the carburetor to limit movementof the throttle valve toward its closedposition, To the third arm of the lever 20 thereris connected one end of a rod 27 whose other end ,is connected to an arm 28 on a shaft 2 9 which xtends crosswise of the vehicle and is journaled in ears 30. and 3| on a bracket 32 which is mounted onthe underside of thefloorboard H. The end of the shaft 29 on which the arm 28 is formed is encircled by a coiledspring 33 which tends to rotate the shaft in the direction to move the throttle valve l3 toward its closed position. To the other end of the shaft 29 there is secured a two-armed lever 3.4 to whose rear arm there is connected a rod 35 which extends through the floor board I I and is connected'to the accelerator pedal 36 of the vehicle. 7

Before the throttle valve of th carburetor of an internal combustion engine which is equipped with the hereinbefore'fdescribed of the adjuncts illustrated in the" drawings reaches the limit of its movement toward its closed position, the link 2| reaches the downward limit of its movement with respect to the arm of the'lever 22 to which it is connected. After this, further movement of the throttle valve toward its closed position results in movement of the lever 22 in a counterclock- Wise direction. When the engine has been warmed up to its normal operating temperature the choke valve' M will be fully opened and, assuming that the lever 22 has been momentarily moved to a position in which the set screw 23 is clear of the cam I6 after the temperature of the engine has reached the prevailing value, the cam v will occupy the position in which it is shown in solid lines in Figure 6 of the drawings in which it is out of the path of movement of the set screw 23 and the'idle speed of the engine will be determined by engagement of theset screw 25 with the abutment26. However, whe'n'the temperature of the engine is below a predetermined value the choke valve I4 will be'closed or only partlyopened and, assuming-again that the lever 22 has been momentarily moved to a. positionin which the set screw 23 is'clear of th 'cam I6 the set screw 23 will upon movement of the "throttle valve toward its closed position come into engagement with the cam l6 before the set screw 25 comes into engagement with the abutment 26 by an amount which varies inversely with the temperature of the engine when it is below the mentioned predetermined value. Still assuming that the lever 22 has been momentarily moved to a position in which the set screw 23 is clear of the cam 16 after the temperature of the engine has reached the prevailing value, the result of all this, of course, is that when the temperature of the engine is below the mentioned predetermined value, the throttle valve will be open to a greater extent when it is at the limit of its movement toward its closed position and the idle speed of the engine will be greater than when the temperature of the engine is up to its normal operating value by an amount which varies inversely with the temperature of the engine.

To start the engine l0, there is provided a starting motor 3'! controlled by a switch which is normally held opened by a spring 38 but may be closed by pushing a button 39 in against the resistance of the spring. Directly behind the button 39 there is located a lever 40 which is mounted at its lower end on a pivot 4| so that it may rock from a position in which an intermediate portion of it engages the button and closes the switch to a position in which it is clear of the button. The lever 40 is normally held in the last mentioned position by a spring which is not shown in the drawings. Through the floor board II opposite the upper end of the lever 40 there extends a rod 43 which is mounted to slide in the direction of its length. The rod 43 has on its end within the driver's compartment a button 44 and on its other end a head 45 with which the upper end of the lever 40 is held in engagement by the spring last men tioned. .The rod 43 is normally held in a position in which the intermediate portion of the lever 40 is clear of the button 39 by a spring 46 but may be pushed in the direction of its length against the resistance of the spring to a position in which the intermediate portion of the lever engages the button and closes the switch by which the starting motor 31 is controlled.

To open the throttle valve l3 when the buttonj44is depressed to start the engine there is provided a lever 41. The lever 41 is journaled at its lower end'in extension of the car 30 on the bracket 32 and from this point extends upwardly, then laterally between the armsof the lever 34 and then forwardly and upwardly nearly to a point in the path of travel of thehead 45 on the rod 43. A spring 48 normally holds the upwardly extending portion of the lever 41 in engagement with a wing 49 on the extension of the ear30 in which the lever 41 is journaled andythe' laterally extending portion of the lever 41 clear of the forward arm and beyond the path of travel of the rear arm of the lever 34.

" To the upper end of the lever 41 there is con nected by a pivot 50 a finger on which there is an car 52 which underlies the lever at a point farther from its upper end than the pivot. The finger 5| is normally held by a spring 53 in a position in which the can 52 engages the underside of the lever and its outer extremity projects into the path of the head 45 on the rod 43 when the lever 41 is at the limit of its movement in a clockwise direction.

When the engine In is not operating the parts of the mechanism which have been described occupy the positions in which they are shown in solid lines in Figures 1 and 2 of the drawings. Depression of the button 44 on the rod 43 to start the engine will rock the lever 40 counterclockwise and after the head 45 on the rod 43 has been moved a short distance downwardly will bring the head into engagement with the outer end of the finger 5|. Thereafter, further depression of the button 44 will rock the lever 41 counterclockwise and bring its laterally extending portion into engagement with the forward arm of the lever 34. Still further depression of the button 44 and the consequent further counterclockwise movement of the lever 41 will rock the lever 34 clockwise and through the shaft 29, the rod 21 and the lever 20 move the throttle valve |3 sufliciently toward its open position topermit the spring 24 to move the lever 22 sufficiently clockwise to move the set screw 23 out of engagement with or out of the path of the cam l6, thus leaving the cam free to assume the position dictated by the thermostat l8. Continued depression of the button 44 will move the lever 41 further counterclockwise until the finger 5| swings out of the path of travel of the head 45 on the rod 43. The position of the parts at this stage of the starting operation is illustrated in Figure 4. Immediately thereafter and before the lever 40 has been moved far enough to close the switch which controls the starting motor 31 the spring 48 will return the lever 41 to its normal position which leaves the spring 33 free to move the throttle valve l3 toward its closed position to the limit permitted by the cam l6. After this has occurred further depression of the button 44 will move the lever 40 to a position in which it closes the switch which controls the starting motor 31 which will put the starting motor into operation and start the engine l0. When the button 44 is released after the engine has started the spring which normally holds the lever 4|] in a position in which it is clear of the button 39 and the spring 46 return the lever 40 and the button 44 to the positions in which they are shown in Figures 1 and 2. In the course of its return to the position in which it is shown in Figures 1 and 2 the head 45 on the rod 43 engages the underside of the outer extremity of the finger 5| and swings it clockwise until it has moved it out of its path of travel and moved upwardly beyond it whereupon the finger is returned to its normal position by the spring 53 with the result that when the button 44 and the lever 40 have reached the positions in which they are shown in Figures 1 and 2 all parts of the mechanism are in positions for another starting operation. The swinging of the finger 5| by the head 45 on the rod 43 to move the finger out of the path of travel of the head is indicated in dash-and-dot lines in Figure 2.

The extent to which the throttle valve |3 moves toward its closed position upon return of the lever 4'l to its normal position after the finger 5| has swung out of the path of travel of the head 45 on the rod 43 is, of course, determined by the position of the cam I6. Consequently, the extent to which the throttle valve is open while the engine is being cranked by the motor 36 to start it will be less when the engine is warmed up to its normal operating temperature than when the temperature of the engine is below the predetermined value which has been referred to and when the temperature of the engine is below this value will vary inversely with the temperature of the engine. Consequently, since the extent to which the throttle valve of the carburetor of an internal combustion engine should be open for the easiest and best starting is an inverse function of the temperature of the engine, the starter-throttle interconnection herein disclosed will result in easier and better starts than the starter-throttle interconnections which are in use.

I claim:

1. In an internal combustion engine, a carburetor by which combustible mixture is sup plied to cylinders of the engine, a choke valve by which the richness of the combustible mixture supplied to the cylinders by the carburetor may be regulated, a thermostat for regulating the position of. the choke valve, 2. throttle valve by which the rate at which combustible mixture is supplied by the carburetor to the cylinders may be regulated, means including the specified thermostat for limiting movement of the throttle valve toward its closed position, a motor by which the engine may be cranked to start it, means by which the motor may be started, and means actuated by the second-specified means for automatically moving the throttle valve toward its opened position during the initial movement of the second-specified means to start themotor and releasing it to permit the throttlev valve to move toward its closed position to the limit permitted by the first-specified means before the motor is started.

2. In an internal combustion engine, a carburetor by which combustible mixture is supplied to cylinders of the engine, a throttle valve by which the rate at which combustible mixture is supplied by the carburetor to the cylinders may be regulated, means including a thermostat for limiting movement of the throttle valve toward its closed position, a motor by which the engine may be cranked to start it, means by which the motor may be started, and means actuated by the second-specified means for automatically moving the throttle valve toward-its opened position during the initial movement of the secondspecified means to start the motor and releasing it to permit the throttle valve to move toward its closed position to the limit permitted by the first-specified means before the motor is started.

3. In an internal combustion engine, a carburetor by which combustible mixture is supplied to the engine, a throttle valve by which the rate at which combustible mixture is supplied by the carburetor to the engine may be regulated, means including a thermostat for limiting movement of the throttle valve toward its closed position, means by which the engine may be cranked to start it, and means actuated by the secondspecified means for automatically moving the throttle valve toward its opened position during the initial movement of the second-specified means to start the engine and releasing it to permit the throttle valve to move toward its closed position to the limit permitted by the firstspecified means before the starting operation is completed.

4. In an internal combustion engine, a carburetor by which combustible mixture is supplied to-cylinders of the engine, a throttle valve by which the rate at which combustible mixture is supplied by the carburetor to the cylinders may be regulated, means for limiting movement of the throttle valvetoward its closed position, a motor by which the engine may becranked to start it, means by which the motor may be started, and means actuated by the second-specified means for automatically moving the throttle valve toward its opened position during the initial movement of the second-specified means to start the motor and releasing it to permit the throttle valve to move to the limit of its movement toward its closed position before the motor is started.

5. In an internal combustion engine, a carburetor by which combustible mixture is supplied to the engine, a throttle valve by which the rate 'at which combustible mixture is supplied to the engine by the carburetor may be regulated, means by which the engine may be cranked to start it, and means actuated by the first-specified means for automatically moving the throttle valve toward its opened position during the initial movement of the first-specified means to start'the engine and releasing it before the starting operation is completed.

6. In an internal combustion engine, a carburetor by which combustible mixture is supplied to cylinders of the engine, a throttle valve by which the rate at which combustible mixture is supplied by the. carburetor to the cylinders may be regulated, a motor by which the engine may be cranked to start it, means by which the motor may be started,.and means actuated by the firstspecified means for automatically setting the throttle valve while the engine is being cranked at a more widely opened position when the engine is cold than when it is warmed up. 1

7. In an internal combustion engine, a carburetor by which combustible mixture is supplied to the engine, a throttle valve by which the rate at which combustible mixture is supplied by the carburetor to the engine may be' regulated, means by which the ngine may be cranked to start it, and means actuated by the first-specified means for automatically setting the throttle valve at a position which varies with the temperature while the engine is being cranked.

8. In combination with a carburetor having a throttle stop element and a movable abutment therefor, thermostatic means for urging said abutment'toward a predetermined position when the temperature is low, means normally urging said stop element against said abutment so as to resist movement of the latter, an automatic starter control, and a device between said control and said stop element to insure momentary releasing of said abutment from said stop element when said control is initially operated.

9. In combination with a carburetor having a throttle and -.stop element movable therewith, an abutment, means for yieldably urging said abutmentxtowards a position in the path of said stop element to limit closing movement of said throttle, means normally urging said stop element into engagement with said abutment so as to resist movement of the latter, an engine starter control and a device to cause said element to momentarily withdraw from and return to its position against said abutment during actuation of said control inits starter actuating direction.

10. In combination with a carburetor having athrottle and a stop element movable therewith, a thermostatically controlled abutment for engagement by said element to limit the closing movement-of said throttle, means normally urging said stop element toward a position to interfere with movement of said element, a control device movable in one direction to actuate an engine starter, and mechanism operable by said device during movement in said direction to successively move said stop element away from said position and return the same thereto so as to release said abutment for thermostatic actuation.

11. In an engine, a carburetor, having a throttle stop element and a movable abutment therefor, thermostatic means for urging said abutment toward a predetermined position when the temperature is low, means normally urging said stop element against said abutment so as to resist movement of the latter, an engine self starter control, and a device forming an operative connection between said control and said stop element to momentarily withdraw said stop element from said abutment and then release said element when said control is operated to start the engine.

12. The combination as specified in claim 10 in which said abutment is thermostatically urged when the temperature is low to a position limitin closing movement of said throttle to its nor-' mal starting position whereby actuation of said starter control device concurrently sets said throttle in starting position.

GILBERT BURRELL. 

